Crystal growth apparatus and method

Abstract

Systems and methods are disclosed for crystal growth using VGF and VB growth processes to reduce body lineage. In one exemplary embodiment, there is provided a method of inserting an ampoule with raw material into a furnace having a heating source, growing a crystal using a vertical gradient freeze process wherein the crystallizing temperature gradient is moved relative to the crystal and/or furnace to melt the raw material and reform it as a monocrystalline compound, and growing the crystal using a vertical Bridgman process on the wherein the ampoule/heating source are moved relative each other to continue to melt the raw material and reform it as a monocrystalline compound.

1 .- 17 . (canceled) 
     
     
         18 . A method for crystal growth, comprising:
 inserting an ampoule with a crucible having a seed and raw material into a furnace having a heating source;   growing a crystal using a vertical gradient freeze process wherein the crystallizing temperature gradient within a heating source is moved relative to the crucible which is stationary to melt the raw material and reform it as a monocrystalline compound; and   growing, at a predetermined crystal growth length, the crystal using a vertical Bridgman process on the ampoule in the furnace wherein the ampoule is moved relative to the heating source which is stationary to continue to melt the raw material and reform it as a monocrystalline compound.   
     
     
         19 . The method of  claim 18  wherein the heating source is a stationary heating source. 
     
     
         20 . The method of  claim 18 , wherein the furnace has a tapered crystal growth region and wherein the predetermined crystal growth length is about 0.25 to about 50 mm above the tapered crystal growth region. 
     
     
         21 . The method of  claim 18 , wherein the furnace further comprises a vertical freeze gradient furnace. 
     
     
         22 . The method of  claim 20  further comprising producing a crystal ingot having no body lineage. 
     
     
         23 . The method of  claim 22 , wherein the crystal ingot is gallium arsenide. 
     
     
         24 . The method of  claim 18 , wherein growing the crystal using the vertical gradient freeze process further comprising growing the crystal at a cooling rate of about 0.1 to about 10.0° C./hour and at a temperature gradient of between about 0.5 and about 10.0° C./cm. 
     
     
         25 . The method of  claim 24 , wherein growing the crystal using the vertical Bridgman process further comprises growing the crystal at a cooling rate of about 0.1 to about 10.0° C./hour and a temperature gradient from about 0.5 to about 10.0° C./cm. 
     
     
         26 . The method of  claim 18  further comprises loading, using a loading crucible, a loading charge of raw Gallium Arsenide material into the crucible to provide a larger amount of raw Gallium Arsenide material to the crucible. 
     
     
         27 . A method for crystal growth, comprising:
 inserting an ampoule with a crucible having a seed and raw material into a furnace having a heating source;   growing a crystal using a vertical gradient freeze process wherein the crystallizing temperature gradient within the stationary heating source is moved relative to the crucible which is stationary to melt the raw material and reform it as a monocrystalline compound; and   growing, at a predetermined crystal growth length, the crystal using a vertical Bridgman-Stockbarger process on the ampoule in the furnace wherein the heating source containing the crystallizing temperature gradient is moved relative to the ampoule which is stationary to continue to melt the raw material and reform it as a monocrystalline compound.   
     
     
         28 . The method of  claim 27 , wherein the furnace has a tapered crystal growth region and wherein the predetermined crystal growth length is about 0.25 to about 50 mm above the tapered crystal growth region. 
     
     
         29 . The method of  claim 27  wherein the furnace further comprises a vertical freeze gradient furnace. 
     
     
         30 . The method of  claim 28  further comprising producing a crystal ingot having no body lineage. 
     
     
         31 . The method of  claim 30 , wherein the crystal ingot is gallium arsenide. 
     
     
         32 . The method of  claim 27 , wherein growing the crystal using the vertical gradient freeze process further comprising growing the crystal at a cooling rate of about 0.1 to about 10.0° C./hour and at a temperature gradient of between about 0.5 to about 10.0° C./cm. 
     
     
         33 . The method of  claim 32 , wherein growing the crystal using the vertical Bridgman-Stockbarger process further comprises growing the crystal at a cooling rate of about 0.1 to about 10.0° C./hour and a temperature gradient from about 0.5 to about 10.0° C./cm. 
     
     
         34 . The method of  claim 27  further comprises loading, using a loading crucible, a loading charge of raw Gallium Arsenide material into the crucible to provide a larger amount of raw Gallium Arsenide material to the crucible. 
     
     
         35 . A product comprising a crystal produced by a process for crystal growth, the process comprising:
 inserting an ampoule with a crucible having a seed and raw material into a furnace having a heating source;   growing a crystal using a vertical gradient freeze process wherein the crystallizing temperature gradient within a heating source is moved relative to the crucible which is stationary to melt the raw material and reform it as a monocrystalline compound; and   growing, at a predetermined crystal growth length, the crystal using a vertical Bridgman process on the ampoule in the furnace wherein the ampoule is moved relative to the heating source which is stationary to continue to melt the raw material and reform it as a monocrystalline compound.